Agree with the red color.
Why no blur?
Rounded corners can be implemented to new users only
I think the blur looks odd and unnecessary. Masks are better in my opinion.
iâm also against blur. doesnât really look like a mask, and is somewhat distracting.
also
contrast seems fine to me, am i missing something? itâs not as good as
but the color-blindness simulation still seems discernable even at extremely low screen brightness or even with night-light filter turned on to the max.
do we have any confirmation itâs actually inaccessible? (could be just a bad simulation, of course)
Blurring blends nicely with the background, regardless of its color. Compare these
Look at the images above. Perhaps the lack of a border is what makes you think it doesnât look like a mask. In any case, I believe that masks should not âlook likeâ anything. They should just disappear.
Edit: with more blur, it hardly looks like a blur anymore while still achieving good blending.
Edit 2: The blur works even better if you adjust the placement of the masks so as to cover mostly the background.
Honestly, the blur makes it look crowded.
How?. The blur doesnât take up any extra space and, as I already mentioned, doesnât look much different from a solid color if its argument is big enough (e.g. blur(25px)).
It might be just me.
Thanks to everyone for the detailed thoughts.
Iâd forgotten that the editor styling is hard-coded 
Changing the defaults seemed like a non-disruptive change since it would only affect new users, but if this will result in inconsistencies for existing users, Iâm not sure itâs worth doing unless we can also fix that too (such as a separate area to configure the I/O styling that the editor can read too, etc).